Method of conveying free-flowing and lump materials upwards and a vibratory elevator embodying said method

ABSTRACT

The present invention relates to methods of conveying freeflowing and lump materials and to vibratory elevators embodying the methods. The method consists in imparting a torsional oscillatory motion to a working element about its axis and a rectilinear oscillatory motion along the axis, the latter motion having a frequency twice that of the former. The working element has a number of rectilinear channels arranged parallel to and a distance away from its axis.

United States Patent l l 1 I I lnventors Rafail Mikhailovich BrumbergVerkhnyaya Radischevskaya ulitsa, l3, kv. 15;

Leonid Moiseevich Trostanetsky, Petrovka 26, kv. 79; Albert LeonidovichKhlebnikov, Verkhnyaya Radischevskaya 13, kv. 4, all

of Moscow, U.S.S.R.

App]. No. 832,211 Filed June 11, 1969 Patented Nov. 16, 1971 PriorityJune 12, 1968 U.S.S.R.

METHOD OF CONVEYING FREE-FLOWING AND LUMP MATERIALS UPWARDS AND AVIBRATORY ELEVATOR EMBODYING SAID METHOD 8 Claims, 2 Drawing Figs.

U.S. Cl 198/220 BA 7 [51] Int. Cl 865g 27/04 [50] Field of Search198/220 (A10), 220 (B10), 220(B20);222/196,161

[56] References Cited UNITED STATES PATENTS 3,421,591 1/1969 Webb..198/220(B10) Primary ExaminerEvon C. Blunk Assistant Examiner-AlfredN. Goodman Att0rneyWaters, Roditi, Schwartz & Nissen ABSTRACT: Thepresent invention relates to methods of conveying free-flowing and lumpmaterials and to vibratory elevators embodying the methods. The methodconsists in imparting a torsional oscillatory motion to a workingelement about its axis and a rectilinear oscillatory motion along theaxis, the latter motion having a frequency twice that of the former. Theworking element has a number of rectilinear channels arranged parallelto and a distance away from its axis.

PATENTED 15 I97] METHOD OF CONVEYING FREE-FLOWING AND LUMP MATERIALSUPWARDS AND A VIBRATORY ELEVATOR EMBODYING SAID METHOD The presentinvention relates to methods of conveying freeflowing and lump materialsupwards and to vibratory elevators embodying said methods. It will comeinto widespread use in foundry, mining, civil engineering, roadconstruction and other industrial applications.

Known in the art are vibratory elevators for conveying freeflowingmaterials which comprise a working element in the form of a spiraltrough or pipe mounted on shock absorbers and carrying a vibratorydrive. The drive imparts helical oscillations to the working element,causing the material to move up the spiral trough or pipe (suchelevators are described in Vibroconveying Machinery Used in Mining by A.O. Spivakovsky and I. F. Goncharevich, Moscow, 1959).

The known vibratory elevators fail, however, to combine high capacitywith adequate compactness. The effective area of section in theseelevators is of limited extent, for the spiral trough or pipe cannotcommonly set at an angle exceeding the angle of friction of the materialagainst the trough or pipe.

There is known a high-capacity method of conveying freeflowing and lumpmaterials by way of a working element which is an inclined pipesubjected to two correlated oscillatory motions, a rectilinear motiondirected along the longitu dinal axis of the working element and atransverse one. The frequency of the longitudinal oscillatory motion istwice that of the transverse oscillatory motion (U.S.S.R. lnventorsCertificate No. 23561 1, class 812,51).

In practical application of the known method when considerable liftingheights are involved, the working element (pipe) needs to be ofconsiderable length, lacking at the same time, as a rule, adequaterigidity. A recourse to ribbing in order to improve the rigidity of theworking element is impractical due to considerations of weight.

An object of the present invention is to provide a method of conveyingfree-flowing and lump materials upwards, which ensures a high-capacityprocess of lifting material a considerable height, both vertically andaslant.

Another object of the present invention is to provide a vibratoryelevator with the working element of adequate rigidity.

The above-mentioned objects are accomplished by the fact that in themethod of conveying free-flowing and lump materials upwards by means ofa working element subjected to two correlated oscillatory motions, oneof them being a rectilinear motion directed along the axis of workingelement and kept, according to the invention, at a frequency twice thatof the other oscillatory motion, said other oscillatory motion of theworking element is a torsional oscillatory motion about its axis.

For correlating the rectilinear oscillatory motion directed along theaxis with the torsional one, the initial phase difference 6 between thedisplacement x of the working element due to the rectilinearoscillations and the angle I of turn of the working element due to thetorsional oscillations, as determined by the equations where A, and Aamplitudes of oscillations,

at torsional frequency,

1= time, is set at l80i40.

The direction in which the material moves in this case coincides withthe positive direction ofx.

The method of conveying free-flowing and lump materials disclosed hereinmakes it possible to develop a vibratory elevator which combines highcapacity with rigidity of the working element and is capable of liftingmaterial both vertically and aslant.

It is of advantage to that end to provide a vibratory elevator fittedwith a drive which imparts two correlated oscillatory motions to theworking element, or, more particularly, to pro vide in the workingelement a number of rectilinear channels arranged parallel to, and adistance away from, the axis.

By virtue of this arrangement, the channels form a closed system ofadequate rigidity and the working element is less strained by thetransverse stresses coming on each channel due to the torsionaloscillatory motion.

The invention will be best understood from the following description ofa preferred embodiment when read in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a cross-sectional view of the working element of an elevator,according to the invention, in a vertical arrangement;

FIG. 2 is a section in line 11-" of FIG. 2.

The method of conveying free-flowing and lump materials upwards consistsin imparting two correlated oscillatory motions to the working elementwhich conveys the material, one of the motions being a rectilinearmotion directed along the longitudinal axis of working element and theother motion is a torsional motion about the axis. The frequency of therectilinear oscillatory motion along the axis is twice that of thetorsional oscillatory motion about the axis.

For correlating the rectilinear oscillatory motion directed along theaxis with the torsional motion, the initial phase difference a betweenthe displacement x of the working element due to the rectilinearoscillations and the angle 1 of turn of the working element due to thetorsional oscillations, as determined by the equations x=A cos(2a)t+e),

I =A,cosmt, where A, and A amplitudes of oscillations;

a): torsional frequency,

t= time is set at li40.

The direction in which the material moves in this case coincides withthe positive direction ofx.

Referring to FIG. 1, the vibratory elevator for conveying free-flowingand lump materials comprises a working element 1 and a vibratory drive 2linked to the working element l.

The working element 1 integrally with the vibratory drive 2 is suspendedfrom a frame 3 by means of suspensions 4 which may be of rubber, springor pneumatic type.

The vibratory drive 2, a mechanical, electric or hydraulic one, isarranged so as to impart rectilinear oscillations along the longitudinalaxis 00 of the working element 1 and torsional oscillations about theaxis, the frequency of the rectilinear oscillations being twice that ofthe torsional oscillations. Particularly suitable to that end is adouble-frequency unbalanced vibratory drive producing high-frequencyoscillations so correlated with the low-frequency oscillations that thefrequency of the former is twice that of the latter and provided withmeans of presetting the required initial phase difference.

The working element 1 for conveying material is arranged eithervertically or aslant depending on the place where the material is to befed.

The working element 1 has several rectilinear channels 5 runningparallel to, and a distance A away from, the axis 0-0 of the workingelement. The distance A is not necessarily the same for all channels 5but must not be equal to zero.

The channels 5 may be formed in the following way. If the workingelement 1 is made up of two concentrically arranged shells 6 and 7, theannular space between the shells can be subdivided by partitions 8 (FIG.2) running all the way along the shells 6 and 7. The channels 5 soobtained have each the shape of an annular sector.

Girdling the top of the working element 1 and held fast to its outsidesurface is a cup 9 with an outlet 10 (FIG. 1). Each of the channels 5communicates with cup 9 through an opening 1].

In operation, the elevator is installed so that its working element 1 issubmerged to a certain depth into free-flowing or lump material 12 piledor placed in a container.

As the vibratory drive 2 is set into operation, it imparts a compositeoscillatory motion to the working element 2, said motion consisting of arectilinear component directed along the axis 0 of the working element 1and a torsional component about the axis. As a result, the free-flowingor lump material 12 moves up the channels 5 and enters the cup 9 throughthe openings 11. From the cup, the material is fed through the opening10 to a suitable intake arrangement.

The movement of material up the channels 5 arranged either vertically oraslant is attributed to the action of a variable force coming into playdue to the variable angular acceleration of the torsional oscillatorymotion imparted to the working element I.

Said force, reaching a maximum during an upstroke of the workingelement, presses the material towards the radial partitions 8 (channelwalls) so that it is carried along by the working element. On thedownstroke of the working element, the force releases its hold of thematerial at the channel walls and the working element overtakes thematerial in moving down. When the angular acceleration changes itsdirection, causing the material to shift to the opposite channel walls,the working element is again on the upstroke, for the frequency of axialoscillations is twice that of the torsional oscillations, and the cycleis repeated.

The parameters of the oscillatory motions obtained during tests whichinvolved lifting of free-flowing and lump materials (sand, molding sand,gravel) were as follows:

amplitude A of torsional oscillations, 0.7-0.8;

amplitude A of axial oscillations, 1.2-1.8 mm.;

frequency of torsional oscillations, 25 c.p.s.;

frequency of axial oscillations, 50 c.p.s.

The diameter of the outside shell 6 was 900 mm. and of the inside shell,600 mm. The mean spacing of radial partitions 8 was 50 mm.

From the tests it has been determined that the initial phase difference6 must be within the limits l40 to 220; the speed of lifting material isbetween 60 and 80 mm. per sec. in this case.

The herein-disclosed vibratory elevator embodying the present methodcompares favorably with the existing vibratory elevators featuring aworking element in the form ofa spiral trough or pipe. The capacity ofthe former by far exceeds that of the latter, provided the outsidediameter of the working element olboth elevators is the same.

The point is that the capacity of an elevator varies directly with thevelocity of material and effective area of section of the workingclement. Since in the conventional vibratory elevators the spiral linerises at a very slow rate, the effective area of section of the spiraltrough or pipe is very small for an elevator of given size. Thedisclosed vibratory elevator conveys material along rectangularchannels. In this case the effective area of section of the workingelement roughly equals the area of the annular space between the outsideand inside shells of the working element or, in other words, isincreased a number of times. This implies that by virtue of aconsiderable increase in the effective area of section of the workingelement of the vibratory elevator provided by the invention its capacityis several times that of the existing vibratory elevators, provided thevelocity of material is the same.

The axis 0-0 of the working element may be arranged not only verticallybut also aslant. The slanting arrangement is sometimes given preferenceespecially when facing the task of loading material into trucks.Furthermore, the slanting arrangement is subject to less pronouncedaccelerations due to the axial and torsional oscillatory motions of theworking element and, consequently, to less intensive inertia loads. Thepresent method of vibroconveying materials and the elevator are alsoapplicable for moving material horizontally and downwards.

What is claimed is:

l. A method of conveying free-flowing and lump materials upwardscomprising imparting two correlated oscillatory motions of a rectilinearmaterial-carrying working element, one

of said oscillatory motions being a rectilinear motion directed alongthe longitudinal axis oft e working element, the other said motion beingtorsional motion of the working element about its longitudinal axis, thefrequency of the rectilinear oscillatory motion being twice that of thetorsional motion, and forming said working element with rectilinearchannels disposed in spaced relation from said axis.

2. A method, as claimed in claim I, in which, for correlating therectilinear oscillatory motion directed along the axis with thetorsional motion, the initial phase difference 6 between thedisplacement x of the working element due to the rectilinearoscillations and the angle 1 of rotation of the working element due tothe torsional oscillations, as determined by the equations x=Acos(2wt+e),

l =A w coswt,

where A, and A amplitudes of oscillations in mm. and degrees,

respectively,

w torsional frequency in c.p.s.,

t= time in seconds, is set at i40.

3. A method as claimed in claim 1 wherein said rectilinear channels areformed on an annular array around said axis.

4. A vibratory elevator for conveying free-flowing and lump bulkmaterial comprising a material carrying working element and a vibratorydrive means for imparting two correlated oscillatory motions to saidworking element, one of said oscillatory motions being a rectilinearmotion directed along the axis of said working element and the othermotion being a torsional motion about said axis; said working elementhaving a number of rectilinear channels arranged parallel to and adistance from said axis, said working element extending with a verticalcomponent from a bulk material entrance to outlets at the top of theelevator.

5. An elevator as claimed in claim 4 wherein said channels are verticaland are in circular array at equal distances from said axis.

6. An elevator as claimed in claim 4 wherein said channels are disposedin an annular array around said axis.

7. An elevator as claimed in claim 4 wherein said working elementcomprises inner an outer spaced shells having smooth surfaces boundingsaid channels.

8. An elevator as claimed in claim 7 wherein said working elementfurther comprises partitions in the space between the shells formingsaid channels.

1. A method of conveying free-flowing and lump materials upwardscomprising imparting two correlated oscillatory motions of a rectilinearmaterial-carrying working element, one of said oscillatory motions beinga rectilinear motion directed along the longitudinal axis of the workingelement, the other said motion being torsional motion of the workingelement about its longitudinal axis, the frequency of the rectilinearoscillatory motion being twice that of the torsional motion, and formingsaid working element with rectilinear channels disposed in spacedrelation from said axis.
 2. A method, as claimed in claim 1, in which,for correlating the rectilinear oscillatory motion directed along theaxis with the torsional motion, the initial phase difference epsilonbetween the displacement x of the working element due to the rectilinearoscillations and the angle phi of rotation of the working element due tothe torsional oscillations, as determined by the equations x Axcos(2omega t+ epsilon ), phi A cos omega t, where Ax and A amplitudes ofoscillations in mm. and degrees, respectively, omega torsional frequencyin c.p.s., t time in seconds, is set at 180* + or - 40*.
 3. A method asclaimed in claim 1 wherein said rectilinear channels are formed on anannular array around said axis.
 4. A vibratory elevator for conveyingfree-flowing and lump bulk material comprising a material carryingworking element and a vibratory drive means for imparting two correlatedoscillatory motions to said working element, one of said oscillatorymotions being a rectilinear motion directed along the axis of saidworking element and the other motion being a torsional motion about saidaxis; said working element having a number of rectilinear channelsarranged parallel to and a distance from said axis, said working elementextending with a vertical component from a bulk material entrance tooutlets at the top of the elevator.
 5. An elevator as claimed in claim 4wherein said channels are vertical and are in circular array at equaldistances from said axis.
 6. An elevator as claimed in claim 4 whereinsaid channels are disposed in an annular array around said axis.
 7. Anelevator as claimed in claim 4 wherein said working element comprisesinner an outer spaced shells having smooth surfaces bounding saidchannels.
 8. An elevator as claimed in claim 7 wherein said workingelement further comprises partitions in the space between the shellsforming said channels.